With the spread of wireless communication systems such as mobile communication systems in recent years, there is a demand for higher performance of transceivers. In particular, low power consumption and low distortion are required in a transmitter. A digital pre-distortion (DPD) system is known as a distortion compensation method for achieving both linearity and power efficiency in a transmission amplifier. Further, as a means for realizing high-speed data communication, the application of MIMO (Multiple-Input Multiple-Output) transmission technology using a plurality of antennas and a transceiver circuit is required. In this case, the transmitter comes to have a plurality of transmission systems.
As a related technology, Patent Document 1 discloses, in a transmitter equipped with a DPD distortion compensation circuit having a plurality of transmission systems, performing updating of the inverse characteristic in the distortion compensation circuit of each transmission system in accordance with the error between transmission data of each transmission system and feedback transmission data corresponding to each of the transmission systems. By this process, distortion of the signal at the output of each transmission system of the transmitter is corrected, and the circuit scale in the transmitter is reduced.